GLP-1 agonists (e.g. Mounjaro) and contraception or HRT
IMPORTANT
If you are currently using a GLP-1 receptor agonist, such as Mounjaro, in combination with any form of contraception or hormone replacement therapy (HRT), please read the following information carefully.
Should you believe this applies to you, or if you would like to discuss it further, we encourage you to contact the surgery.
What are GLP-1 agonists?
GLP-1 receptor agonists are a class of medication that includes tirzepatide and semaglutide. These drugs may be known by various brand names, such as Mounjaro, Ozempic, or Wegovy. They can only be prescribed and administered by a qualified healthcare professional, such as a doctor or nurse.
GLP-1 agonists are primarily used to manage type 2 diabetes and, in some cases, to support weight loss. They work by slowing down the rate at which food leaves the stomach, helping to regulate appetite and blood sugar levels.
You may currently be prescribed one of these medications on the NHS for type 2 diabetes, or you may be accessing it privately for weight management purposes.
| Medicine | Brand name examples |
|---|---|
| Tirzepatide | Mounjaro |
| Semaglutide | Ozempic, Wegovy, Rybelsus |
| Exenatide | Bydureon BCise |
| Liraglutide | Saxenda, Diavic, Victoza |
| Dulaglutide | Trulicity |
| Lixisenatide | Contained in Suliqua |
I am taking the pill. Will using a GLP-1 agonist affect my contraception?
The impact on contraception can vary depending on the specific GLP-1 agonist you are using.
If you are taking tirzepatide (Mounjaro), it is recommended that you use additional contraceptive protection, such as condoms, for four weeks after starting the medication and for four weeks following any dose increase. This is because tirzepatide may affect how your body absorbs oral contraceptives. You may also wish to consider using a non-oral form of contraception while taking tirzepatide.
For other GLP-1 agonists, such as semaglutide, exenatide, liraglutide, dulaglutide, or lixisenatide, there is currently no evidence to suggest that they reduce the effectiveness of the oral contraceptive pill.
I have diarrhoea and vomiting with my GLP-1 agonist, and I take the contraceptive pill, what should I do?
Diarrhoea and vomiting are known side effects of GLP-1 agonists and may reduce the effectiveness of the oral contraceptive pill.
If you vomit within three hours of taking your pill, or experience severe diarrhoea for more than 24 hours, please follow the standard guidance for missed pills.
If symptoms continue, consider switching to a non-oral form of contraception or using condoms in addition to your current method to ensure effective protection.
What about non-oral methods of contraception e.g. the coil, implant, injection, patch or ring, could these be affected by GLP-1 agonists?
GLP-1 agonists do not affect the effectiveness of non-oral contraception methods. This means options such as the contraceptive implant, injection, intrauterine device (IUD), intrauterine system (IUS), or vaginal ring remain reliable while taking a GLP-1 agonist.
No additional precautions are needed if you are using one of these methods.
I am planning to switch from one type/brand of GLP-1 to another, does the contraception advice remain the same?
If you are transitioning to tirzepatide (Mounjaro) from another GLP-1 agonist, it’s important to take extra precautions with contraception.
You should use condoms in addition to your oral contraceptive pill for:
-
Four weeks after switching to tirzepatide, and
-
Four weeks after any dose increase.
Continue taking your pill as prescribed. Alternatively, you may wish to consider switching to a non-oral contraceptive method, such as the implant, injection, or IUD, while using tirzepatide.
I need emergency contraception and I’m taking a GLP-1 agonist; will it work?
It is not yet known whether GLP-1 agonists affect the effectiveness of emergency contraception pills.
The copper intrauterine device (IUD), also known as the coil, is the most effective form of emergency contraception. It is not affected by diarrhoea, vomiting, or any GLP-1 agonist medications.
If you require emergency contraception, please inform your healthcare provider about all medications you are taking, including any GLP-1 agonists, so the most suitable option can be recommended.
Can I take a GLP-1 agonist during pregnancy?
It is important to use effective contraception while taking a GLP-1 agonist, as these medicines are not recommended during pregnancy.
If you become pregnant while taking a GLP-1 agonist, please contact your doctor as soon as possible.
You should also plan to stop the medication several weeks before trying to conceive, as GLP-1 agonists can remain in the body for some time. The table below outlines how many weeks in advance you should stop treatment before planning a pregnancy, depending on the specific medication.
| Medicine | Time to stop before planning a pregnancy |
|---|---|
| Tirzepatide (Mounjaro) | One month |
| Semaglutide (Ozempic, Wegovy, Rybelsus) | Two months |
| Exenatide (Bydureon BCise) | 12 weeks |
I’m on HRT and taking Mounjaro – what do I need to know?
If you are taking oral progestogen as part of your hormone replacement therapy (HRT)—such as Utrogestan, Norethisterone, or Medroxyprogesterone—please be aware that tirzepatide (Mounjaro) may affect the effectiveness of your HRT. This could mean that your HRT may not adequately protect your endometrium (womb lining).
We recommend that you contact the surgery to arrange an HRT review. During this review, we may consider adjusting your dose or switching you to an alternative form of medication.
If you use non-oral forms of HRT, such as a patch, gel, or Mirena coil, this interaction does not apply, and no additional precautions are necessary.
This patient information is based on a leaflet from the Faculty of Sexual and Reproductive Healthcare (FSRH) and the Primary Care Women’s Health Society. This information is provided for guidance only and should not replace professional medical advice. Decisions about contraception should always be made in consultation with a healthcare professional, especially if you have any questions or concerns. Please be aware that no method of contraception is 100% effective, and there is always a risk of pregnancy. The Faculty of Sexual and Reproductive Healthcare accepts no liability for any decisions made regarding contraception or the outcomes of those decisions. To view the FSRH leaflet, click here – Patient-information-GLP-1-agonists-and-contraception
